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    SCIP

    Solving Constraint Integer Programs

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    heur_pscostdiving.c File Reference
    Implementation files (.c files) » SCIP Default Plugins » Default Primal Heuristics

    Detailed Description

    LP diving heuristic that chooses fixings w.r.t. the pseudo cost values.

    Author
    Tobias Achterberg

    Definition in file heur_pscostdiving.c.

    #include "scip/heuristics.h"
    #include "scip/heur_pscostdiving.h"
    #include "scip/pub_heur.h"
    #include "scip/pub_message.h"
    #include "scip/pub_misc.h"
    #include "scip/pub_var.h"
    #include "scip/scip_heur.h"
    #include "scip/scip_mem.h"
    #include "scip/scip_numerics.h"
    #include "scip/scip_prob.h"
    #include "scip/scip_sol.h"
    #include "scip/scip_var.h"
    #include <string.h>

    Go to the source code of this file.

    Macros

    #define HEUR_NAME   "pscostdiving"
     
    #define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the pseudo cost values"
     
    #define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING
     
    #define HEUR_PRIORITY   -1002000
     
    #define HEUR_FREQ   10
     
    #define HEUR_FREQOFS   2
     
    #define HEUR_MAXDEPTH   -1
     
    #define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE
     
    #define HEUR_USESSUBSCIP   FALSE
     
    #define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY
     
    #define DIVESET_ISPUBLIC   TRUE
     
    #define DEFAULT_MINRELDEPTH   0.0
     
    #define DEFAULT_MAXRELDEPTH   1.0
     
    #define DEFAULT_MAXLPITERQUOT   0.05
     
    #define DEFAULT_MAXLPITEROFS   1000
     
    #define DEFAULT_MAXDIVEUBQUOT   0.8
     
    #define DEFAULT_MAXDIVEAVGQUOT   0.0
     
    #define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1
     
    #define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0
     
    #define DEFAULT_BACKTRACK   TRUE
     
    #define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15
     
    #define DEFAULT_LPSOLVEFREQ   0
     
    #define DEFAULT_ONLYLPBRANCHCANDS   TRUE
     
    #define DEFAULT_RANDSEED   103
     
    #define divesetAvailablePscostdiving   NULL
     

    Functions

    static SCIP_DECL_HEURCOPY (heurCopyPscostdiving)
     
    static SCIP_DECL_HEURFREE (heurFreePscostdiving)
     
    static SCIP_DECL_HEURINIT (heurInitPscostdiving)
     
    static SCIP_DECL_HEUREXIT (heurExitPscostdiving)
     
    static SCIP_DECL_HEUREXEC (heurExecPscostdiving)
     
    static SCIP_DECL_DIVESETGETSCORE (divesetGetScorePscostdiving)
     
    SCIP_RETCODE SCIPincludeHeurPscostdiving (SCIP *scip)
     

    Macro Definition Documentation

    ◆ HEUR_NAME

    #define HEUR_NAME   "pscostdiving"

    Definition at line 47 of file heur_pscostdiving.c.

    ◆ HEUR_DESC

    #define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the pseudo cost values"

    Definition at line 48 of file heur_pscostdiving.c.

    ◆ HEUR_DISPCHAR

    #define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING

    Definition at line 49 of file heur_pscostdiving.c.

    ◆ HEUR_PRIORITY

    #define HEUR_PRIORITY   -1002000

    Definition at line 50 of file heur_pscostdiving.c.

    ◆ HEUR_FREQ

    #define HEUR_FREQ   10

    Definition at line 51 of file heur_pscostdiving.c.

    ◆ HEUR_FREQOFS

    #define HEUR_FREQOFS   2

    Definition at line 52 of file heur_pscostdiving.c.

    ◆ HEUR_MAXDEPTH

    #define HEUR_MAXDEPTH   -1

    Definition at line 53 of file heur_pscostdiving.c.

    ◆ HEUR_TIMING

    #define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

    Definition at line 54 of file heur_pscostdiving.c.

    ◆ HEUR_USESSUBSCIP

    #define HEUR_USESSUBSCIP   FALSE

    does the heuristic use a secondary SCIP instance?

    Definition at line 55 of file heur_pscostdiving.c.

    ◆ DIVESET_DIVETYPES

    #define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY

    bit mask that represents all supported dive types

    Definition at line 56 of file heur_pscostdiving.c.

    ◆ DIVESET_ISPUBLIC

    #define DIVESET_ISPUBLIC   TRUE

    is this dive set publicly available (ie., can be used by other primal heuristics?)

    Definition at line 57 of file heur_pscostdiving.c.

    ◆ DEFAULT_MINRELDEPTH

    #define DEFAULT_MINRELDEPTH   0.0

    minimal relative depth to start diving

    Definition at line 64 of file heur_pscostdiving.c.

    ◆ DEFAULT_MAXRELDEPTH

    #define DEFAULT_MAXRELDEPTH   1.0

    maximal relative depth to start diving

    Definition at line 65 of file heur_pscostdiving.c.

    ◆ DEFAULT_MAXLPITERQUOT

    #define DEFAULT_MAXLPITERQUOT   0.05

    maximal fraction of diving LP iterations compared to node LP iterations

    Definition at line 66 of file heur_pscostdiving.c.

    ◆ DEFAULT_MAXLPITEROFS

    #define DEFAULT_MAXLPITEROFS   1000

    additional number of allowed LP iterations

    Definition at line 67 of file heur_pscostdiving.c.

    ◆ DEFAULT_MAXDIVEUBQUOT

    #define DEFAULT_MAXDIVEUBQUOT   0.8

    maximal quotient (curlowerbound - lowerbound)/(cutoffbound - lowerbound) where diving is performed (0.0: no limit)

    Definition at line 69 of file heur_pscostdiving.c.

    ◆ DEFAULT_MAXDIVEAVGQUOT

    #define DEFAULT_MAXDIVEAVGQUOT   0.0

    maximal quotient (curlowerbound - lowerbound)/(avglowerbound - lowerbound) where diving is performed (0.0: no limit)

    Definition at line 71 of file heur_pscostdiving.c.

    ◆ DEFAULT_MAXDIVEUBQUOTNOSOL

    #define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1

    maximal UBQUOT when no solution was found yet (0.0: no limit)

    Definition at line 72 of file heur_pscostdiving.c.

    ◆ DEFAULT_MAXDIVEAVGQUOTNOSOL

    #define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0

    maximal AVGQUOT when no solution was found yet (0.0: no limit)

    Definition at line 73 of file heur_pscostdiving.c.

    ◆ DEFAULT_BACKTRACK

    #define DEFAULT_BACKTRACK   TRUE

    use one level of backtracking if infeasibility is encountered?

    Definition at line 74 of file heur_pscostdiving.c.

    ◆ DEFAULT_LPRESOLVEDOMCHGQUOT

    #define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

    percentage of immediate domain changes during probing to trigger LP resolve

    Definition at line 75 of file heur_pscostdiving.c.

    ◆ DEFAULT_LPSOLVEFREQ

    #define DEFAULT_LPSOLVEFREQ   0

    LP solve frequency for diving heuristics

    Definition at line 76 of file heur_pscostdiving.c.

    ◆ DEFAULT_ONLYLPBRANCHCANDS

    #define DEFAULT_ONLYLPBRANCHCANDS   TRUE

    should only LP branching candidates be considered instead of the slower but more general constraint handler diving variable selection?

    Definition at line 78 of file heur_pscostdiving.c.

    ◆ DEFAULT_RANDSEED

    #define DEFAULT_RANDSEED   103

    initial random seed

    Definition at line 79 of file heur_pscostdiving.c.

    ◆ divesetAvailablePscostdiving

    #define divesetAvailablePscostdiving   NULL

    Definition at line 260 of file heur_pscostdiving.c.

    Function Documentation

    ◆ SCIP_DECL_HEURCOPY()

    static SCIP_DECL_HEURCOPY ( heurCopyPscostdiving  )
    		static

    copy method for primal heuristic plugins (called when SCIP copies plugins)

    Definition at line 98 of file heur_pscostdiving.c.

    References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPheurGetName(), and SCIPincludeHeurPscostdiving().

    ◆ SCIP_DECL_HEURFREE()

    static SCIP_DECL_HEURFREE ( heurFreePscostdiving  )
    		static

    destructor of primal heuristic to free user data (called when SCIP is exiting)

    Definition at line 112 of file heur_pscostdiving.c.

    References HEUR_NAME, NULL, SCIP_OKAY, SCIPfreeBlockMemory, SCIPheurGetData(), SCIPheurGetName(), and SCIPheurSetData().

    ◆ SCIP_DECL_HEURINIT()

    static SCIP_DECL_HEURINIT ( heurInitPscostdiving  )
    		static

    initialization method of primal heuristic (called after problem was transformed)

    Definition at line 132 of file heur_pscostdiving.c.

    References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPcreateSol(), SCIPheurGetData(), and SCIPheurGetName().

    ◆ SCIP_DECL_HEUREXIT()

    static SCIP_DECL_HEUREXIT ( heurExitPscostdiving  )
    		static

    deinitialization method of primal heuristic (called before transformed problem is freed)

    Definition at line 152 of file heur_pscostdiving.c.

    References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPfreeSol(), SCIPheurGetData(), and SCIPheurGetName().

    ◆ SCIP_DECL_HEUREXEC()

    static SCIP_DECL_HEUREXEC ( heurExecPscostdiving  )
    		static

    execution method of primal heuristic

    Definition at line 171 of file heur_pscostdiving.c.

    References NULL, SCIP_CALL, SCIP_DIDNOTRUN, SCIP_DIVECONTEXT_SINGLE, SCIP_OKAY, SCIPgetNContImplVars(), SCIPgetNContVars(), SCIPgetNVars(), SCIPheurGetData(), SCIPheurGetDivesets(), SCIPheurGetNDivesets(), SCIPperformGenericDivingAlgorithm(), and SCIP_Diveset::sol.

    ◆ SCIP_DECL_DIVESETGETSCORE()

    static SCIP_DECL_DIVESETGETSCORE ( divesetGetScorePscostdiving  )
    		static

    returns a score for the given candidate – the best candidate maximizes the diving score

    Definition at line 197 of file heur_pscostdiving.c.

    References FALSE, MAX, MIN, SCIP_Bool, SCIP_OKAY, SCIP_Real, SCIPdivesetGetRandnumgen(), SCIPgetVarPseudocostVal(), SCIPisEQ(), SCIPisGT(), SCIPisLT(), SCIPrandomGetInt(), SCIPvarGetRootSol(), SCIPvarIsBinary(), SCIPvarMayRoundDown(), SCIPvarMayRoundUp(), and TRUE.